Optical testing instrument.



PATENTED AUG. 9, 1904.

E. EIMER. OPTICAL TESTING INSTRUMENT.

APPLICATION FILED DEG-17. 1903.

N0 MODEL.

UNITED STATES Patented August 9, 1904.

PATENT OFFICE.

OPTICAL TESTING INSTRUMENT.

SPECIFICATION forming part of Letters Patent No. 767,334, dated August9, 1904.

Application filed December 17, 1903. Serial No. 185,469.

To (ti/Z whom it warty concern:

Be it known that I, ERNEST EIMER, a citizen of the United States ofAmerica, and a resident of Muskegon, Muskegon county, Michigan, haveinvented a certain new and useful Improvement in Optical TestingInstruments, of which the following is a specification.

My invention contemplates an improved, simple, andexceedingly-inexpensive form of optical instrument for testing thevision. is especially adapted for measuring the extent of the limits ofdistinct vision in different individuals and for thus determining thefocal length of the lens necessary to correct imperfect sight.

In the preferred embodiment of my invention one advantage and valuablefeature consists in pivotally or hingedly connecting the different partsin such manner that they can be readily folded up, so as to adapt thedevice in its entirety for transmission through the mail. Thus in thisway my improved testing instrument can be readily and conveniently sentthrough the mail to persons desiring to order spectacles or glasses.

Another prominent feature of my invention consists in constructing allthe positively-connected parts, except the lens, of cardboard, therebyrendering the device exceedingly cheap and inexpensive in character andof such nature that none of the different cardboard parts can becomedisconnected or misplaced.

Another feature consists in providing the testing instrument with a dialand a rotary pointer, the dial being graduated and provided withdifferent words or characters, which, through the medium of a privatekey, enable the optician to determine the character of lens necessaryfor the person ordering the glasses.

The nature and advantages of my invention will, however, hereinaftermore fully appear.

In the accompanying drawings, Figure 1 is a perspective illustrating themethod of using my improved testing instrument for testing the vision orsight of people desiring to order glasses or spectacles. Fig. 2 is aplan of my improved testing instrument. Fig. 3 is a rear (N0 model.)

the folded position of the lens-holder in dot-- ted lines. Fig. 5 is anenlarged vertical section on line 5 5 in Fig. 2'.

As thus illustrated, my improved optical testing instrument fordetermining the character of defect in vision consists of a lensholderA, provided, preferably, with a doubleconvex lens a, a handle a, and aflexible hinge connection (1?, the latter being provided for flexiblyconnecting the lens-holder with the arm or pointer B. This arm B, whichhas a pointed end 6, adapted to serve as a pointer, has its other endpivotally connected with the said hinge at b and is pivotally connectedat the intermediate point 72 with the dial C. The target D, whichcorresponds in shape to the lens-holder A, is provided with a handleportion (Z and with a flexible hinge connection (5, the latter flexiblyconnecting the targetwith the arm 0 of the said dial. This hingeconnection cl is pivotally connected with the arm 0 at (P. sists of twoapertured pieces of cardboard, secured together with the lens betweenthem. The said dial is provided with a series of graduations 0,corresponding to the different degrees of myopia, and with anotherseries of graduations, 0 corresponding to the different degrees ofpresbyopia. Preferably the threeletter words 0 are arranged opposite thegraduations 0, while the four-letter words 0* are arranged opposite thegraduations 0 Thus the word Mad indicates the greatest degree of myopia,while the least amount of myopia is indicated by the word Bag. In asimilar manner the smallest degree of presbyopia is indicated by theword Lace, while the greatest degree of this sort of defect in thevision is indicated by the word Hart.

The target D can be provided on'its face that is to say, on its surfacefacing the lenswith lettering in small type.

The manner of using the device thus constructed is obvious. The persondesiring to order spectacles or glasses simply holds the lens and thetarget in vertical positions, as shown in Fig. 1, and then moves thetarget The said lens-holder preferably con-,

back and forth until the printing is clearly distinguishable andreadable through the lens. The person thus using the instrument can thensimply observe the location of the pointer on the dialthat is to say,can take note of the word toward which the pointer (Z is pointing. Theoptician when advised of this particular word then understandsimmediately through the medium of a private key the character of thedefect in the vision.

Thus it will be seen that I provide an optical testing instrument whichcan be readily folded up and placed in an envelop or package andtransmitted without danger of breakage through the mails, thusfacilitating the ordering of spectacles or glasses.

Inasmuch as all of the parts of the instrument are positively connectedtogether, the connections being either flexible or pivotal or hinge-likein character, it is obvious that the parts can be readily flattened intoa suitable condition for transmission through the mail and that noportion of the instrument can become detached and lost.

What I claim as my invention is 1. An instrument for testing vision,consisting of a lens-holder and a target connected for relative swingingadjustment toward and away from each other, and a graduated indicatingdevice, all adapted to be folded into a flat or practically flatcondition.

2. An instrument for testing vision, comprising a lens-holder and atarget connected for relative adjustment, and a graduated dial providedwith a pointer adapted to be rotated about its axis by the relativeadjustment of the lens-holder and target, all adapted to be folded intoa flat or practically flat condition.

3. An instrument for testing vision, comprising a plurality of pieces ofcardboard pivotally and flexibly connected, and including a lens-holderand a target connected for relative swinging adjustment toward and awayfrom each other, and a graduated indicating device, all adapted to befolded into a flat or practically fiat condition.

4:. An instrument for testing vision, comprising a lens-holder and atarget connected for relative swinging adjustment toward and away fromeach other, and a graduated indicating device adapted to be operated byrelative adjustment of the lens-holder and target, said indicatingdevice being provided with a series of arbitrary key-words representingdifferent degrees of defect in vision.

5. An instrument for testing vision, comprising a lens-holder and atarget, a dial pivotally and flexibly connected with the target, and apointer pivotally connected with the dial and flexibly and pivotallyconnected with the lens-holder, all adapted to be folded into a flat orpractically flat condition.

6. An instrument for testing vision, com.- prising a lens-holder, atarget, and suitable indicating means, all of said parts beingpositively connected together by pivotal or hingelike connecting means,whereby no part can become detached from the others.

7. An instrument for testing vision, comprising a lens-holder and atarget connected for relative adjustment, a dial provided with a pointerand pivotal connection between the dial and pointer, said dial andpointer being adapted to be adjusted relatively by the movements of thelens-holder and target toward and away from each other.

8. An instrument for testing vision, comprising a lens-holder and atarget, and suitable indicating means, said lens-holder having both aflexible and a pivotal connection with the indicating means.

9. An instrument for testing vision, comprising a lens-holder and atarget, and suitable indicating means, said target having both aflexible and a pivotal connection with the indicating means.

Signed by me at Muskegon, Michigan, this 17th day of November, 1903.

ERNEST EIMER.

\Vitnesses:

MILo G. PRAY, HARRY A. RIETDYK.

